Superheater and boiler combination



Jill 10,1928.

v O J-R'. HANNAN EI'AL SUPERHEATER AND BOILER COMBINATION :5 Sheets-Sheet 2 Filed Sept. 1, 1925 O OO O O O O O O O O O O O O O O l/VVENIDRS JOHN ROBE/Z7 HANNA/V1! W/L L MM ERNESZEA/GZ/SH 5 THE/f? ATTORNEYS July 10, 1928. 1,677,081 J. R. HANNAN ET AL SUPERHEATER mm BOILER COMBINATION Filed Sept 1, 1925' a sheets-sheet 3 4 IIIVUYTORS JOHN ROBERT HAN/14H WILL/11M ERNEST ENGLISH BY THEIR HTTORIYEYJ Patented July 10, 1928.

UNITED STATES PATENT OFFICE.

JOHN ROBERT HANNAH, OF SHORTLANDS, ENGLAND, AND WILLIAM ERNEST ENGLISH,

V OF BISHOPSTON, SOUTH WALES.

SUPERHEATER AND BOILER COMBINATION.

Application filed Septeniber 1, 1925, Serial No. 53,845, and in Great Britain July 9, 1925;

Our'invention relates to improvements in steam superheater and boiler combinations particularly in connection with water tube boilers of the horizontal type and has for is principal object to provide a superheater which is efiicient in operation, can be readily removed from the boiler and, owing to its position in the said boiler, requires less heating surface and is consequently very economical.

Superheaters of the horizontal type situated between the boiler tubes and known as the interdeck type of superheaters have been proposed but in such construction of superheaters their removal from a boiler is matter of considerable diificulty Where several boilers are situated in close proximity.

According to our invention we provide super-heaters in which the tube elements are arranged in an inclined or semi-vertical position, say for example, at an angle of about 60 to the horizontal, between the boiler tubes of a boiler so that when in place the said tubes are parallel or approximately parallel to, the diagonals of the boiler tube centres; this permits of the said tube elements being readily withdrawn through the upper part of the boiler and enables the said tube elements to receive the benefit of the heating effect from the whole of the products of combustion as efficiently as is obtained in the interdeck type without the tendency of the said tube elements to sag under high temperature conditions which is liable to occur when the said tubes are ar ranged in a horizontal position.

lVith superheaters constructed according to our invention we may also obtain economy in heating by employing the counter current principle whereby the saturated steam suply is preferably connected to the superiieater header in such a way as to cause the steam to pass through the nest of superheater tubes situated in the second pass of the boiler gases and then to pass down the nest of superheater tubes situated in the first pass of the boiler gases so that the saturated steam first abstracts heat from comparatively low temperature gases and on its passage into the second nest of tubes receives its final degree of superheat from comparatively high temperature gases.

One form of our invention is shown in the accompanying drawings, in which:

Figure 1 is a sectional View taken at right angles to the bo ler axis;

Fig. 2 is a similar sectional view showing Figure 1 illustrates in section, as much of a water tube boiler of the horizontaltype as is necessary to shew, by way of example, the application thereto of a superheater constructed and arranged in accordance with this invention and Figure 2 is a similar view to Figure 1 showing a modified construction and arrangement of the su erheater to that shewn in Figure 1. In tese examples shewn we employ a pair of headers A disposed above the boiler tube level, secured in housing boxes B arranged on each side of the boiler at the upper part thereof and in proximity to and parallel with the steam drums C. The superheater tubes D are connected to the headers A by any known, or suitable means, have their main longitudinal parts arranged in diagonal intervals between the boiler tubes, and are supported by diagonal series of the boiler tubes. In the construction shewn' in Figure 1 the superheater tubes are arranged within the boiler tube space below on the diagonal line of the boiler tubes which have been omitted to give the required space for the superheater tubes, and in the modified construction shewn in Figure 2 the superheater tubes are arranged between diagonal linesof boiler tubes. The housing boxes B are each provided with a cover 6 which can be readily removed and replaced, so that access can be had to the headers A and any desired superheater tube can be disconnected therefrom and withdrawn through the open upper end of the said box, or, if required, the, headers may be disconnected from the inlet and outlet pipes in communication with the boiler and the superheated steam chests respectively, so that the whole superheater element may be withdrawn or be inserted through the open end of the said box.

Any suitable means, such for example, as diaphragms may be arranged in the headers to secure the working of the flow of steam and gases on the counter current principle already referred to.

Figure 3 illustrates such a modification of a water tube boiler of the horizontal type with depending vertical superheaters constructed according to our invention and arranged to obtain economy in heating by employing the counter current principle. The boiler is construetech as is clearly shown, to give a first and secondpassto the boiler gases.

A and A are the. headersand F indicates a diaphragm to arrest the flowof steam.

The saturated steam enters the header A as indicated by the arrows at a a and passes down through the nest of superheater tubes D situated in the second pass E of the boiler gases and then passes up and out by the header A as indicated by the arrow at a and then down the second nest of superheater tubes as indicated by the arrow at and so down the second nest of superheater tubes D situated in the first pass E of the boiler gases and out through the header A at a a so that the saturated steam first abstracts heat from the comparatively low temperature gases and on its passage through the second'nest of tubes receives its final degree of superheat from comparatively high temperature gases nearer the furnace.

The arrangement of the superheater tubes in accordance with this invention may be applied withinwide limits to various types of superheaters and the invention is not limited to the particular construction of superheater hereinbei'ore described and illustrated in the accompanying drawing.

lVhat we claim is The combination of a water tube boiler of the horizontal type having its tubes arranged in spaced parallel rows, each row lying in a plane inclined at a substantial angle to the vertical, and a superheater comprising headers, disposed above the boiler tube level, and tube elements communicating with said headers and extending into the space between two adjacent rows of boiler tubes.

In testimony whereof we have signed our names to this specification.

. JOHN ROBERT i-IANNAN.

WILLIAM ERNEST EJGLISH. 

